Side entry sub

Abstract

A side entry sub has an elongated main body with a longitudinal bore and a side passage intersecting the longitudinal bore. A removable hub has a nose portion which threadably engages mating threads in the side passage, with a resilient seal on the nose portion providing a fluid seal with the main body. The threads are formed such that a flange on the hub advances into contact with the main body with a desired contact force as holes in the flange come into alignment with threaded holes in the main body. Threaded flange bolts through the flange holes engage the threaded holes in the main body. Locking washers are used on the flange bolts. The removable hub is structurally connected to the main body by the threaded connection and contact of the flange with the main body, and pressure and fluid-sealed by the resilient seal.

We claim: 
     
       1. An apparatus, comprising:
 an elongated main body comprising a longitudinal bore therethrough, said longitudinal bore forming a wall in said main body, said main body further comprising a side passage extending through said wall and intersecting said longitudinal bore, said side passage comprising internal threads therein; 
 a removable hub comprising a longitudinal bore therethrough, and further comprising:
 a nose portion comprising threads engageable with said internal threads in said side passage; 
 a flange; and 
 an outermost end comprising external threads; 
 
 a resilient seal element sealing between said main body and said removable hub, when said removable hub is threadably engaged with said internal threads in said side passage of said main body; and 
 wherein, when said removable hub is fully threadably engaged with said main body, said flange is in contact with said main body, and one or more fasteners are positioned through holes in said flange and into said main body, thereby preventing rotation of said removable hub. 
 
     
     
       2. The apparatus of  claim 1 , wherein said nose portion of said removable hub comprises a seal groove, and wherein said resilient seal element is disposed in said seal groove. 
     
     
       3. The apparatus of  claim 2 , wherein said one or more fasteners comprise threaded flange bolts extending through said holes in said flange and threadably engaging threaded holes in said main body. 
     
     
       4. The apparatus of  claim 3 , further comprising locking washers between said flange bolts and said flange. 
     
     
       5. The apparatus of  claim 1 , wherein said internal threads in said side passage and said threads of said nose portion of said removable hub comprise parallel thread forms. 
     
     
       6. The apparatus of  claim 1 , wherein said main body comprises threaded connections at either end. 
     
     
       7. A side entry sub, comprising:
 an elongated main body comprising a longitudinal bore therethrough, said longitudinal bore forming a wall in said main body, said main body further comprising a side passage extending through said wall and intersecting said longitudinal bore, said side passage comprising internal threads therein; 
 a removable hub comprising a longitudinal bore therethrough, forming a flowpath through said removable hub and into said longitudinal bore of said main body when said removable hub is threadably engaged with said main body, wherein said removable hub further comprises a nose portion comprising threads engageable with said internal threads in said side passage and a seal groove, an outermost end comprising external threads, and a flange positioned between said nose portion and said outermost end; 
 a resilient seal element positioned in said seal groove and sealing between said main body and said removable hub, when said removable hub is threadably engaged with said main body; and 
 wherein, when said removable hub is fully threadably engaged with said main body, said flange is in contact with said main body, and one or more fasteners are positioned through holes in said flange and into said main body, thereby preventing rotation of said removable hub. 
 
     
     
       8. The side entry sub of  claim 7 , wherein said fasteners comprise threaded flange bolts extending through said holes in said flange and threadably engaging threaded holes in said main body. 
     
     
       9. The side entry sub of  claim 8 , further comprising locking washers between said flange bolts and said flange. 
     
     
       10. The side entry sub of  claim 8 , wherein said threads in said side passage and said threads on said nose portion of said removable hub are formed so that said flange contacts said main body with a desired contact force when said holes in said flange are aligned with said threaded holes in said main body. 
     
     
       11. The side entry sub of  claim 10 , wherein said internal threads in said side passage and said threads of said nose portion of said removable hub comprise parallel thread forms. 
     
     
       12. The side entry sub of  claim 11 , wherein said external threads on said outermost end of said removable hub comprise hammer union threads. 
     
     
       13. The side entry sub of  claim 12 , wherein said main body comprises threaded connections at either end.